Astronomska jedinica

Astronomska jedinica (hrvatska kratica AJ ili aj, međunarodna kratica eng. AU od Astronomical Unit) je mjerna jedinica za duljinu. Međunarodni ured za mjere i utege predlaže oznaku za astronomsku jedinicu ua.^[1]

Upotrebljava se u astronomiji, te je približno jednaka prosječnoj udaljenosti Zemlje od Sunca, odnosno velikoj poluosi Zemljine orbite. Trenutno prihvaćena vrijednost te udaljenosti je jednaka 149 597 870 691 ± 30 metara (približno 150 milijuna kilometara).^[1] Do 2012. astronomska je jedinica bila definirana u okviru Zemljine orbite, no odonda se definira kao točno 149 597 870 700 metara.^[2]

Izvori

↑ ^1,0 ^1,1 The International System of Units (SI), 8. izdanje, 2006, strana 126
↑ RESOLUTION B2 on the re-definition of the astronomical unit of length, Beijing: International Astronomical Union, 31. kolovoza 2012., http://www.iau.org/static/resolutions/IAU2012_English.pdf, "The XXVIII General Assembly of International Astronomical Union recommends [adopted] that the astronomical unit be re-defined to be a conventional unit of length equal to exactly 149,597,870,700 metres, in agreement with the value adopted in IAU 2009 Resolution B2"

[The_International_System_of_Units-1] 1,0 ^1,1 The International System of Units (SI), 8. izdanje, 2006, strana 126

[2] RESOLUTION B2 on the re-definition of the astronomical unit of length, Beijing: International Astronomical Union, 31. kolovoza 2012., http://www.iau.org/static/resolutions/IAU2012_English.pdf, "The XXVIII General Assembly of International Astronomical Union recommends [adopted] that the astronomical unit be re-defined to be a conventional unit of length equal to exactly 149,597,870,700 metres, in agreement with the value adopted in IAU 2009 Resolution B2"

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